Safety valve



Aug. 10, 1948. 5. BAXTER ET AL SAFETY VALVE Filed June 6, 1944 INVENTORS Ben amin Baxter ATTORNEYS 5am gel/VI. Jfiandarzfan ML W24 Patented Aug. 10, 1948 SAFETY VALVEv Benjamin Baxter and; Samuel Mt Kandarian,

Fowler, Calif.

Application June 6, 1944',Serial' No. 538,931

The present invention relates generally to a safety valve for use in connection with gas welding systems, and in particular the invention is directed to, and it is an object to provide, a safety valve for use between: the high pressure gastank and the pressure regulator of such a welding system; the safety valve being operative to prevent any high pressure surge against the pressure regulator when the pressure from the tank is initially turned into said system. The safety valve is thus eiiective to prevent damage to'the equipmenhand particularly the pressure regulator, and avoids possible injury to the operator.

A further object of this invention is to. incorporate a safety valve, for the above purpose, in the manually controlled main tank valve as a unitary part thereof.

Another object of this invention is to provide a safety'valve, as in the preceding paragraph, which automatically functions, when the main tank valveis initially andpartly'opened, to check any-pressure surge and-permit only of gradual increase of the pressure-beyond-said main tank valve, said safety valve being mechanically and positively movedto aninoperative or non-restrictive position upon continued openlngmovernent of said main tank valve to full open position.

A further object of the inventionis to produce a simple and inexpensive device,.and yet onewhich Willbe exceedingly eliectlve for-the purpose for which it is designed.

These objects we accomplish. b means of such structure and relative. arrangementcf partsas will fully appear by a perusalof. the following specification and claims.

.In. the drawings similar charactersot reference indicate. corresponding parts inthe several views:

Figure l is. an. elevation, mainly in section, of a main. tank valve embodying-the present invention; the main valve being. shown in partly open position,v and the safety valve shown-in pressure equalizing. position.

Figure 2. is .a similar view, but illustrates the main valve, as well as the safety valve, in open position Figure 3 is a cross section on line 3-3 =of- Fig. 1.

Figure 4 is a sectional elevation. of a. modified form. of the safety valve, detached.

Referring now more, particularly to. the characters of. reference on. thed-rawings, the numeral l indicates an axially elongatedmain valve. body into which. a main valve head 2 is threaded from one end said head being. formed on the inner. end of .a stem 3' which. projects axially out of the upper. end of. the body through a packinggland ll.

-6- Claims. (Cl. 277-49),

2 Ahand whe'el5is fixed" to the outer end otth stem 3 for the control of the valve head 2.

Thoma-in body l includes an; axial bore 6*which extends from the end of said-:body opposite hand wheel 5 inwardly to a termination" at and in communication with an :annular upwardly facing valve seat l-iormedi for cooperation with. thetmain valve head 2 the latter including a valvewasher 8- adapted toengage with th seat 1 upon axially inward movement-of saidheadl. An outlet pas sage '9 enters the body I vlaterallyand communicates with the inner end oft-bore 6 when the main valve. head 2 is in open. position. -A threaded fitting l-flsurrounds. the lower end of bore :6 and. is adapted forzconnection with the high pressure gas tank otthe: welding system, while the outlet passa-ge it extends through a lateral fittin I; l. which is adapted for connection with-the conduitlnot shown) which leads to the-pressure regulator of said sys tem-l The above .describcd-. structure comprises the main tank valve ofoa. gaswelding system, and is substantially conventional. .To this main. .tank valve. the. present invention. is incorporatedv as follows:.

The lower. endporti'on. of. the bore. 6 is enlarged, as at 12, to forma downwardly ifacing annular valve seat.l3 .A..p1ug.valve M-issIidabIydispoSed inv the enlarged bore 12,. andtheinner end of said valve. is. of frusto-conical configuration, as. shown, for cooperative .matching engagementwith the downwardly facing. valve, seat 13; the. valve [4 initially being, closed against seat l3 by means of a compression-spring f5 engaged between the lower end. of said .valve and a stopecollar |6 press-fitted into the enlarged bore 12. g

Exteriorly the slidableplug ,valve. I4 is formed with a .pluralityotl circumferentially v spaced longitudinally extending hannels !'I. which permit of unrestricted. pressure flow by said valv when the latter is open relative to the seat l3.

The valve M includes an axial boreala therethrough; the flower or outer end portion l9of said bore. being enlarged to receive, the head of a bleed control screw"2'0 which is threaded intothe bore. I at from theenlarged portionv [.9 thereof, and which controls andlimits pressureflow through the valve l4 whenthe latter isclosed. .A filter 2| in the. enlarged portion #9 or bore l8prevents access of foreign matter into said valve. 7 V

The valve M will preferably-be constructed in the .manner shown in detail inour co.-pending application Serial No. 520,450; "filed. J anuary 31, 1944;, now Patent Number $389,881,, granted .November 27, 19.45.

An axial push rod 22 is threaded through a spider 23 in bore 6 intermediate valve seats I and I3; said push rod including a non-circular, axial shank 24 which projects upwardly through valve seat 1 into a, matching non-circular, axial bore 2'! in the main valve head 2. The main valve head 2 and the push rod 22 are formed with opposite threads; the head 2 preferably being righthand threaded, while the push rod 22 is left-hand threaded.

The lower end of the push rod 22 is clear of the inner, frusto-conical end of the slidable plug valve 14 when the main valve head 2 is in valve;

closing position with the washer 8 seated against the valve seat I. When the hand wheel 5' is' initially turned to a limited extent by the operator and causes partial opening of the main'valve by moving washer 8 slightly away from seat],

the push rod 22 turning on its reverse threads tion, by the operator, of the: hand Wheel 5 in a main 'valve'opening direction, the head 2, together with the washer 8, moves to full open position, as shown in Fig. 2. When this occurs the push rod 22, due to its reverse threading, advances downwardly a sumcient distance to engage and push the valve I4 to its full open position, whereupon the pressure flow throu h the device is unrestricted. As is evident, downward movement of the push rod on its reverse threads upon upward movement of the head 2 is made possible through the medium. of the non-circular shank 24 riding in the matching bore 25.

- When the head 2 is again returned to closing position relative to the seat I, the push rod 22 retracts and permits the valve I I to close, ready for the next valve opening operation.

In Fig. 4 there is illustrated a modified form of the plug valve; the valve here being shown at Ma and including, as previously, side channels l'la. Here, however, the flow restricting means through the valve comprises an extremely restricted. axial bore I811 which extends through said valve from an enlarged bore portion 19a to the apex of said valve. The enlarged bore portion I 9a which opens from the valve in the direction of the tank includes therein a filter 2 la, to assure against foreign'matter gaining access and plugging at restricted bore I 8a. When this form of valve is used in the device, it functions in exactly the same manner as described in connection with the valve [4.

From the foregoing description it will be readily seen that we have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the inventiomas defined by the appended claims.

Having thu described our invention, what we claim as new and useful and desire to secure by Letters Patent is: I

l. A safety valve comprising a body having a bore therein, opposed valve seats in said bore, a manually controlled valve mounted in the body for opening and closing movement relative to said one valve seat, another valve mounted in the body for opening and closing movement relative to the other seat, said valve being initially closed and said other valve having a restricted flow passage therethrough, and means actuated by said manually controlled valve operative to cause opening of said other valve in one direction after predetermined opening movement of said manually controlled valve in the opposite direction; said manually controlled valve being threaded into the body for rotation, and said means including a push rod threaded into the body for counter- "rotation to engage and open said other valve,

and an instrumentality connected between said manually controlled valve and the push rod arranged to impart rotation of the latter without restricting opening movement of either valve.

2. A safety valve comprising a body having a bore therein, oppositely facing axially alined valve seats in said bore, a main valve threaded into the body for opening or closing movement relative to one seat, another valve slidably mounted in the body for opening or closing movement relative to the other seat, said valves being initially closed, means to bleed pressure past said other valve toward the main valve, an axially disposed push rod threaded in the bore between said valve seats without restricting flow therebetween, said push rod being threaded counter to the main valve whereby rotation of said push rod in the same direction as the main valve rotates to open, causes said push rod to engage and open said other valve, axially extensible means connected between the main valve and push rod to rotate the latter when said main valve is rotated, and hand means to rotate said main valve.

3. A valve as in claim 2 in which said axially extensible means comprises a non-circular shank cooperatively engaged in a matching bore.

4. A safety valve comprising a body having a bore therein, oppositely facing axially alined valve seats in said bore, a main valve threaded into the body for opening or closing movement relative to one seat, another valve slidably mounted in the body for opening or closing movement relative to the other seat, said valves being initially closed, means to bleed pressure past said other valve toward the main valve, an axially disposed push rod threaded in the bore between said valve seats without restricting flow therebetween, said push rod being threaded counter to the main valve whereby rotation of said push rod in the same direction as the main valve rotates to open, causes said push rod to engage and open said other valve, a non-circular shank projecting axially from said push rod into a matching bore in the main valve, and hand means to rotate the main valve.

5. A safety valve having a straight bore therein, oppositely facing valve seats in said bore, a main valve threaded into the body for opening and closing movement relative to one seat, another valve slidably mounted in the bodyfor opening and closing movement relative to the other seat, a spring urging said other valve toward the corresponding seat, both valves being initially closed, a spider in the bore between the seats, an axial push rod threaded through said spider, the push rod being threaded counter to the main valve, a non-circular shank projecting axially from the push rod toward the main valve, the latter having a matching axial bore therein in 5 which said shank slidably engages, the push rod engaging and opening said other valve upon rotation of the main valve in a direction to open the same but only after partial opening thereof, and hand means to rotate the main valve.

6. A safety valve comprising a casing having an inlet and an outlet, a valve seat adjacent the inlet, a valve seat adjacent the outlet, a valve for the inlet, yieldable means normally holding the inlet valve against its seat, a valve for the outlet, manually operable means for respectively moving the outlet valve against and away from its seat, open restricted passage means leading from one side of the inlet valve to the other whereby when the outlet valve is moved away from its seat, communication will be opened from the inlet through the restricted passage means and to the outlet, and means responsive to the movement of the outlet valve and operable to engage and open the inlet valve after the outlet valve has been moved away from its seat a predetermined distance.

BENJAMIN BAXTER. SAMUEL M. KANDARIAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 714,747 Rowley Dec. 2, 1902 1,072,796 Vance Sept. 9, 1913 1,230,499 Matheson June 19, 1917 15 2,308,643 Bucknam Jan. 19, 1943 2,336,282 Mueller Dec. 7, 1943 FOREIGN PATENTS Number Country Date 7,878 Great Britain 1894 

